As time allows, I'll try and fill some gaps in the inventory of the Grand Fleet in the Bucket, starting with HMS Queen Mary, Lion's and Princess Royal's luckless half sister.
Queen Mary's differences to the earlier Splendid Cats were mostly internal, but she could be told from the other two by the different arrangement of her forward 102mm guns and her stern walk. Less easy to spot were differences in searchlight arrangement aft, the shape of the foremast and the shape of the middle funnel. As completed, she is portrayed in a Battleship Grey livery with dark green turret tops, which seems to have been standard in the last years before the war (an even darker shade of grey shows on some photographs of Bellerophon- and St.Vincent-class battleships, but I've not found any of Queen Mary painted in this dark hue).
By early 1915, Queen Mary had received some refits. Most visible was the addition of fire control directors and struts to the foremast to stiffen it for the added weight. The top of the foremast was shortened and the w/t rig slightly re-arranged. The ship received an early form of camouflage paintjob, which was also seen on contemporary pictures of HMS Tiger; in this guise, at least these two battlecruisers went into the battle of the Dogger Bank.
By 1916, the four 47mm saluting guns abreast the aft funnel were landed and two 76mm AA guns were installed. The torpedo nets were removed in late 1915 or early 1916. I have not found out whether painting the turret tops green was continued into the war or not; available photographs are pretty inconclusive about that matter. In this guise - the RN's late war light grey livery was not adopted until after Jutland - Queen Mary was lost.
I hope I got everything; there are virtually no photographs of Queen Mary after being retrofitted with directors.